Temperature-dependent photoluminescence of CuAlO2 single crystals fabricated by using a flux self-removal method

• Published in: Journal of the Korean Physical Society Vol. 65; no. 7; pp. 1068 - 1072
• Main Authors: Nam, Y. S., Yoon, J. S., Ju, H. L., Chang, S. K., Baek, K. S.
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.10.2014; 한국물리학회
• Subjects: Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Theoretical; 물리학; CuAlO; Temperature dependent photoluminescenc
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.65.1068

The temperature-dependent behavior of p-type transparent semiconducting oxide CuAlO 2 single crystals prepared by using a flux self-removal method in alumina crucibles was investigated through transmittance and photoluminescence (PL) measurements at temperatures from 12 K to room temperature. The low-temperature (12 K) PL spectrum shows two weak, broad emission peaks, one at 3.52 eV and the other at 3.08 eV, which we assign to excitonic emission and to defectrelated emission originating from copper vacancies. The positions of the PL peaks as functions of temperature exhibit a normal behavior satisfying the standard Varshini law, and the Debye temperature is found to be θ D = 610 ± 80 K. The exciton-binding energy of the CuAlO 2 single crystal is estimated to be 49 meV from the PL intensity change with temperature.